Joseph Nicholas Aguilera told police he did not remember punching an elderly homeless man to death in Phoenix on July 11.

Aguilera, a 30-year-old Army veteran, did not deny being the man captured on surveillance footage at a nearby gas station but told police he "did not remember assaulting anyone at that date and time," according to court documents obtained by New Times.

After police sent out still images of that surveillance footage to media outlets on Friday, police got a call about the man in the photo that evening.

Aguilera's brother-in-law identified him for police, and Aguilera's family turned over the shirt and San Francisco Giants hat seen in the surveillance footage. When police found Aguilera, he was wearing the camouflage pants he was seen wearing in the video.

A witness -- apparently the lone witness to the deadly beating -- identified Aguilera as the man he was punch the elderly man, according to the court documents.

That witness was at the gas station near 27th Avenue and McDowell Road around 8 p.m. on July 11, filling up on gas. He told police he watched as Aguilera left the convenience store and approached the elderly man, saying, "I'm going to fuck you up" -- apparently without any provocation.

Aguilera then swung at the elderly man -- who was in a defensive position -- and punched him unconscious at the bus stop, the witness said.

The victim, whom police haven't been able to identify yet, never regained consciousness and was pronounced dead at a hospital. The suspect ran away after punching the man.

Aguilera told police that it was him on the video, even confirming what he was holding in his hand on his way out -- lottery tickets.

But he said he didn't remember any assault. Aguilera was booked into jail on a charge of second-degree murder, and his bond was set at $500,000.

Aguilera's criminal history includes a 2006 DUI conviction. Charges were dismissed against him in a 2003 domestic violence case.